Paul:
As the attached note says 24:00:00 is allowed. But it also says that it
is
an alternate representation for 00:00:00 (of the following day). This
is not what you want. In the presence of a leap second you want
24:00:00 to be the final second of the current day and 00:00:00 the
following second of the next day. We need to craft some careful wording
to cover this situation.
All the best, Ashok
-----Original Message-----
From: Schluter, Paul (MED, GEMS-IT) [mailto:Paul.Schluter@med.ge.com]
Sent: Wednesday, December 11, 2002 4:59 PM
To: W3C XML Schema Comments list
Subject: RE: 24:00:00 allowed or not
Wednesday, December 11, 2002,
Ashok and James,
I noticed this thread in the W3C email archives regarding
whether 24:00:00 should be allowed or not. It _must_ be
allowed, because the time "24:00:00" can actually exist
when a leap-second is inserted at midnight.
Leap-second insertion typically occurs every 18 months or
so, principally to account for the gradual slowing of the
earth's rotation over time (roughly 1.7 msec/day/century).
Leap seconds are supported by NTP (RFC-1305) and SNTP (RFC-2030)
and are recognized in numerous other areas such as astronomy
where accurate timekeeping is required.
Regards,
Paul Schluter
===========================================================
Date: Tue, 23 Apr 2002 06:40:06 -0700
Message-ID:
<E5B814702B65CB4DA51644580E4853FB019EEB02@red-msg-12.redmond.corp.micros
oft.com>
From: "Ashok Malhotra" <ashokma@microsoft.com>
To: "James Clark" <jjc@jclark.com>, <www-xml-schema-comments@w3.org>
Subject: RE: 24:00:00 allowed or not?
24:00:00 is allowed. It is an alternate representation for 00:00:00
All the best, Ashok
===========================================================
-----Original Message-----
From: James Clark [mailto:jjc@jclark.com]
Sent: Tuesday, April 23, 2002 6:19 AM
To: www-xml-schema-comments@w3.org
Subject: 24:00:00 allowed or not?
ISO 8601 section 5.3.2 allows 24:00:00 as a representation of midnight.
Appendix D of XML Schema Part 2 says that the hh field runs between 0
and 23, but there is no mention of 24:00:00's not being allowed as a
difference between XML Schema and ISO 8601. I'm left uncertain as to
whether 24:00:00 is allowed or not.
James